-
Notifications
You must be signed in to change notification settings - Fork 0
/
retry.go
203 lines (183 loc) · 5.71 KB
/
retry.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
// Copyright (c) 2016 Uber Technologies, Inc.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
package retry
import (
"errors"
"math"
"time"
xerrors "github.com/m3db/m3/src/x/errors"
"github.com/uber-go/tally"
)
var (
// ErrWhileConditionFalse is returned when the while condition to a while retry
// method evaluates false.
ErrWhileConditionFalse = errors.New("retry while condition evaluated to false")
)
type retrier struct {
initialBackoff time.Duration
backoffFactor float64
maxBackoff time.Duration
maxRetries int
forever bool
jitter bool
rngFn RngFn
sleepFn func(t time.Duration)
metrics retrierMetrics
}
type retrierMetrics struct {
success tally.Counter
successLatency tally.Histogram
errors tally.Counter
errorsNotRetryable tally.Counter
errorsFinal tally.Counter
errorsLatency tally.Histogram
retries tally.Counter
}
// NewRetrier creates a new retrier.
func NewRetrier(opts Options) Retrier {
scope := opts.MetricsScope()
errorTags := struct {
retryable map[string]string
notRetryable map[string]string
}{
map[string]string{
"type": "retryable",
},
map[string]string{
"type": "not-retryable",
},
}
return &retrier{
initialBackoff: opts.InitialBackoff(),
backoffFactor: opts.BackoffFactor(),
maxBackoff: opts.MaxBackoff(),
maxRetries: opts.MaxRetries(),
forever: opts.Forever(),
jitter: opts.Jitter(),
rngFn: opts.RngFn(),
sleepFn: time.Sleep,
metrics: retrierMetrics{
success: scope.Counter("success"),
successLatency: histogramWithDurationBuckets(scope, "success-latency"),
errors: scope.Tagged(errorTags.retryable).Counter("errors"),
errorsNotRetryable: scope.Tagged(errorTags.notRetryable).Counter("errors"),
errorsFinal: scope.Counter("errors-final"),
errorsLatency: histogramWithDurationBuckets(scope, "errors-latency"),
retries: scope.Counter("retries"),
},
}
}
func (r *retrier) Attempt(fn Fn) error {
return r.attempt(nil, fn)
}
func (r *retrier) AttemptWhile(continueFn ContinueFn, fn Fn) error {
return r.attempt(continueFn, fn)
}
func (r *retrier) attempt(continueFn ContinueFn, fn Fn) error {
attempt := 0
if continueFn != nil && !continueFn(attempt) {
return ErrWhileConditionFalse
}
start := time.Now()
err := fn()
duration := time.Since(start)
attempt++
if err == nil {
r.metrics.successLatency.RecordDuration(duration)
r.metrics.success.Inc(1)
return nil
}
r.metrics.errorsLatency.RecordDuration(duration)
if xerrors.IsNonRetryableError(err) {
r.metrics.errorsNotRetryable.Inc(1)
return err
}
r.metrics.errors.Inc(1)
for i := 1; r.forever || i <= r.maxRetries; i++ {
r.sleepFn(time.Duration(BackoffNanos(
i,
r.jitter,
r.backoffFactor,
r.initialBackoff,
r.maxBackoff,
r.rngFn,
)))
if continueFn != nil && !continueFn(attempt) {
return ErrWhileConditionFalse
}
r.metrics.retries.Inc(1)
start := time.Now()
err = fn()
duration := time.Since(start)
attempt++
if err == nil {
r.metrics.successLatency.RecordDuration(duration)
r.metrics.success.Inc(1)
return nil
}
r.metrics.errorsLatency.RecordDuration(duration)
if xerrors.IsNonRetryableError(err) {
r.metrics.errorsNotRetryable.Inc(1)
return err
}
r.metrics.errors.Inc(1)
}
r.metrics.errorsFinal.Inc(1)
return err
}
// BackoffNanos calculates the backoff for a retry in nanoseconds.
func BackoffNanos(
retry int,
jitter bool,
backoffFactor float64,
initialBackoff time.Duration,
maxBackoff time.Duration,
rngFn RngFn,
) int64 {
backoff := initialBackoff.Nanoseconds()
if retry >= 1 {
backoffFloat64 := float64(backoff) * math.Pow(backoffFactor, float64(retry-1))
// math.Inf is also larger than math.MaxInt64.
if backoffFloat64 > math.MaxInt64 {
return maxBackoff.Nanoseconds()
}
backoff = int64(backoffFloat64)
}
// Validate the value of backoff to make sure Int63n() does not panic.
if jitter && backoff >= 2 {
half := backoff / 2
backoff = half + rngFn(half)
}
if maxBackoff := maxBackoff.Nanoseconds(); backoff > maxBackoff {
backoff = maxBackoff
}
return backoff
}
// histogramWithDurationBuckets returns a histogram with the standard duration buckets.
func histogramWithDurationBuckets(scope tally.Scope, name string) tally.Histogram {
sub := scope.Tagged(map[string]string{
// Bump the version if the histogram buckets need to be changed to avoid overlapping buckets
// in the same query causing errors.
"schema": "v1",
})
buckets := append(tally.DurationBuckets{0, time.Millisecond},
tally.MustMakeExponentialDurationBuckets(2*time.Millisecond, 1.5, 30)...)
return sub.Histogram(name, buckets)
}